There is known a vehicle headlamp in which a lamp unit having a light source and a reflector, which reflects light emitted from the light source, is arranged inside a lamp outer casing formed by a cover and a lamp housing.
The lamp unit is rotatably (tiltably) supported by a support member such as a bracket and is rotated by a driving force of an actuator (see, e.g., Patent Documents 1 and 2).
Regarding the vehicle headlamp in which the lamp unit rotates about a swivel shaft serving as a pivot, there is known a vehicle headlamp in which the swivel shaft is supported by the bracket so that it can rotate in a horizontal direction, and a shaft holding member preventing the swivel shaft from being separated from the bracket is attached to the bracket (see, e.g., Patent Document 3).
In the vehicle headlamp, the lamp unit is rotated (tilted) in an upper-lower direction by the actuator, so that a so-called leveling adjustment (leveling operation) of adjusting a deviation of an optical axis, which is changed by a weight of a vehicle-loaded object, is performed. Also, the lamp unit is rotated in a left-right direction by the actuator, so that a so-called swivel adjustment (swivel operation) of changing a direction of the optical axis to follow a traveling direction of a vehicle is performed.
In the actuator of the vehicle headlamp disclosed in Patent Document 1, a pair of gear portions is provided at left and right sides of an output gear and rack members that are respectively movable in a front-rear direction are meshed with the respective gear portions. When the two rack members are synchronously moved in the same direction along the front-rear direction, the output gear is moved in the front-rear direction and the lamp unit is rotated in the upper-lower direction, so that the leveling operation is performed. When the two rack members are synchronously moved in opposite directions along the front-rear direction, the output gear is rotated and the lamp unit is rotated in the left-right direction, so that the swivel operation is performed.
On the other hand, in the actuator of the vehicle headlamp disclosed in Patent Document 2, two driving portions each of which has a worm and a shaft portion are provided at a side and a rear of the output gear respectively. The worm positioned at the side is movable in the front-rear direction integrally with the shaft portion and the shaft portion positioned at the rear is connected to a slide member that holds the output gear. By a rotation of the worm positioned at the rear of the output gear, the shaft portion positioned at the rear is moved in the front-rear direction, so that the output gear and the slide member are integrally moved in the front-rear direction. Thereby, the lamp unit is rotated in the upper-lower direction, so that the leveling operation is performed. At this time, the worm positioned at the side and the gear portion are integrally moved in the front-rear direction. By a rotation of the worm positioned at the side, the output gear is rotated, so that the lamp unit is rotated in the left-right direction and the swivel operation is performed.
Patent Document 1: JP2007-128856A
Patent Document 2: JP2009-183033A
Patent Document 3: JP2008-94196A